Rotatable antenna system



July 11, 1933. P. s. CARTER ROTATABLE ANTENNA SYSTEM Filed Aug. 25, 1930 4 Sheets-Sheet l INVENTOR P. S. CARTER BY 7%MW ATTORNEY jaly 11, 1933.

P. s. CARTER 1,918,180

ROTATABLE ANTENNA SYSTEM Filed Aug. 25, 1930 4 Sheets-Sheet 2 INVENTOR P.S. CARTER ATTORNEY y 1933. P. s. CARTER ROTATABLE ANTENNA SYSTEM Filed Aug. 25, 1930 4 Sheets-Sheet 3 INVENTOR P. s. CARTER BY 7%W ATTORNEY Patented July 11, 1933 are unit

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PHILI'? STAATS CARTER, OF PORT JEFFERSON, NEW YORK, ASSIGNOR TO RADIO con- PonA'rIon or AMERICA, A CORPORATION or DELAWARE R-OTATABLE ANTENNA SYSTEM:

Application filed August 25, 1930.

I In my copending application, Serial Number 460,467, filed June 11, I930, assigned to the Radio Corporation of America, I have disclosed and antenna comprising pairs oi angularly disposed or diverging conductors, long, relatiye to the Working wave length hav-- ing a plurality of standing waves at the Working wave length thereon. By proper choice ofthe angle between the conductors relative to their length, I have taught the art that radiant action will occur principally along the bisector of the angle formed by the con ductors; and, by the use of a parallelly disposed similar pair of conductors spaced apart along the bisector of the angle and odd number of quarter Wave lengths, radiation or reception With the antenna will become sharply unidirectional along the bisector of the angle formed by the conductors, the unidirectivity depending upon the relative phase excitation of the pairs of diverging conductors.

In United States Patent 1,884,006, granted October 25, 1932, to Nils E. Lindenblad, an antenna comprising parallel stag ered conductors, long relative to the worliing Wave length and having standing Waves at the working Wave length thereon has beendisclosed having sharp directivity at an angle with the conductors depending upon the length of the conductors and the working frequency. By the use of a suitable number ofconductors properly staggered and spaced apart, a system has been disclosed which is sharply unidirectional at a fixed-angle relative to the Wires forming the antenna system.

As the structures referred to hereinabove are large and fairly expensive, it is desirable to use a single antenna structure for trans.

beam of energy.

Accordingly, the main object of my present invention is to providemeans for rotating antennae,- preferably of the character described, either continuously or through any Serial No. 477,544.

connected in parallel, one motor at the antenna and the other at the control point. Aw cordingly, rotation of the antenna by a separate driving motor will cause rotation of the armature of the induction motor at the antenna and consequently a corresponding 1o tation of the armature of the induction inotor at the control point which, by a scale and pointer arrangement will indicate the angular position of the antenna. Of course, if desired the drive motor may be omitted and rotation of the armature of the motor at the control point will cause a corresponding rotation of the motor, at the antenna, which may be mechanically coupled to it for rotating the antenna.

Still a further object of my present invention is to provide in combination with a rotatable antenna system preferably as dc scribed, means for melting sleet from the antenna system.

In the accompanying drawings which are illustrative only of. my present invention,

Figures l and 2 are, respectively, plan and elevational views of an antenna system, comprising diverging pairs of wires, one pair actin as a reflector and another as an antenna, having means for rotating the same,

Figures 3 and 4 are views of a modification similar to Figures 1 and 2,

Figure 5 is a wiring diagram for the an tenna system shown in Figures 1 to 4 in elusive,

Figures 6 and 7 illustrate an antenna system comprising a plurality of staggered linear conductors, long, relative to the working Wave length having remote control means for rotating the antenna through any desired angle,

Figure 8 is a wiring diagram illustrating a method for coupling the antenna shown in Figures 6 and 7 to high frequency apparatus,

Figure 9 illustrates a heating circuit which may be applied to the system shown in Figures l to 5 inclusive, and,

Figure 10 illustrates a heating circuit which may be applied to the system shown in Figure 8.

Referring to Figures 1 and 2, upon a rotatable member 2, mounted in any suitable fashion upon a base 4:, there are fixed three arms 6 having posts or supporting elements 8 thereon. To the supporting elements 8 there are fixed cross pieces or arms 10 which in turn supportthe angularly disposed conductors 12, 14: forming an antenna structure, and, similar parallel diverging wires 16, 18 forming a reflecting system spaced apart along the bisector of the angle formed by the conductors, an odd number of quarter wave lengths as disclosed more fully in my copending application referred to. As shown, the system is sharply unidirectional along the bisector of the angle formed by the conductors, and, in order to increase the directivity in a. direction perpendicular to the plane of the conductors shown in Figure l, the system is duplicated in a parallel plane as illustrated, for example, at 18 in Figure 2.

Coupling to high frequency apparatus is made through a stationary transmission line 20, shown in Figure 2, through slip rings 22 and rotatable transmission line 24. This is shown more clearly in Figure 5 which gives the wiring diagram of the system shown in Figures 1 and 2; As shown in Figure 5, the rotatable transmission line24r is coupled to the antenna and reflector structures through tun ing traps 26, 28 suitably supported between cross pieces 10 and 30 shown in Figure 2. The tuning trap structure is also more fully described and explained in my copending application Serial Number 460,467 filed June 11, 1930.

In order to continliouslyrotate the antenna system of Figures 1 and 2 about shaft 32 to which slip rings 22'are fixed, a gear 34 is attached to member 2 and cooperatively associated through suitable gearing mechanism 36 as shown, to motor 38, which, if desired, is remotely controlled at point 40 whereby by closing of switches thereat continuous rotation of the antennasystem shown in Figures 1 and 2 may be obtained. Of course, rotation to any desired angle may be obtained by manual rotation of the system but, it is preferred to utilize electrical means such as described in connection with Figure 6 hereinafter, for that purpose. Transmis sion line 20 connected to the insulated rings 22, is coupled to suitable high frequency apparatus either a receiver or transmitter, as desired.

Electrically, the antenna system shown in Figures 3 and 4 is identical with that described in connection with Figures 1 and 2,

and consequently the Wiring diagram shown' in Figure 5 is equally applicable thereto. However, the rotatable under-structure for the antenna is somewhat dilferent. Shaft 32 shown in Figure 4: is fixed to a base member 42. Angularly disposed arms 44 diverging at an angle corresponding to the angle formed by the antenna and reflector conductors are maintained in fixed position by cross piece 46 and rotatably mounted about shaft 32 by virtue of castors or wheels 48 engaging a circular track 50 on base member 42. Rotation of the antenna system may be accomplished by means of a motor 38 driving the rotatable antenna under-structure through worm gear mechanism 52, pulley 54;, belt or chain 56, and pulley 58 fixed to the arms 44.

One of the conductors forming the rotatable transmission line 24 may be'grounded, and a single line 60 led back to high frequency apparatus suitably located with reference to the antenna system.

The supports for the antenna conductors may,'as shown, comprise cross pieces or arms 62 fixed to bars 44 carrying supporting elements 6 1 thereon to which are fixed, in any suitable fashion, the conductors forming the antenna system.

Referring to the modification shown in Figures 6, 7 and 8, a plurality of parallel linear conductors having standing waves at a wave length correspondingto the working frequency thereon, are suitably held and fixed upon U-shaped arms 72, in turn fixed to a rotatable member 74, in staggered position in accordance with the teachings given by Nils E. Lindenblad, in. his United States Patent 1,884,006, supra. Radiant action of the system will occur predominantly, 'as taught in the Lindenblad application, referred to, inthe direction of the arrow shown in Figure 7. Connection to high frequency apparatus 76 may be accomplished through slip rings 78 and a suitable transmission line 80. I

Rotation of the antenna system continuously or through any desired angle may be accomplished through driving motor 85, gears 83, 84, driving shaft 86 in turn fixed to supporting member 74 and rotatably mounted in a base 88.

In orderto rotate the antenna through a predetermined angle, from a remote control point GP, induction motors 90,92 are'provided having their fields paralleled by conductors 94, supplied'with energy through transmission line 96, and having their armatures paralleled by conductors 98. Accordingly, relative rotation of'a suitable pointer and dial arrangement 100 fixed to the armature of the motor situated at the controlling point will correspond exactly to the rotation of the armature of motor 90 and in turn rotation of the antenna system; The latter is independently rotated by drive motor 85 through pinion gear 83. The remote driving and indicating system, may, of course, be applied to any of the modifications described.

In order to couple the conductors to high frequency apparatus, they may be coupledas disclosed in the patent of Nils E. Lindenblad, referred to. For example, they may be coupled as shown in Figure 8. Thus, as shown the conductors 70 may be coupled to a rotating transmission line 100 through impedance matching devices 102 also rotatable with the antenna structure.

As sleet deposits on the antenna conductors would tend to vary the electrical characteristics thereof, to say nothing of increased strength required of the conductors due to increased loading and wind resistance caused by the accumulation of the frozen deposits on the conductors, it is desirable, and, as already indicated it is a further object of this invention to provide for the heating of the rotatable conductors in order to remove therefrom the frozen deposits. In my copending application, Serial Number 474,086, filed August 9, 1930, I have disclosed heating circuits for removing sleet from antenna systems of the type described in Figures 1 to 5 inclusive. These circuits may be applied to the systems described hereinabove.

For example, as shown in Figure 9, rotatabletransmissionlin-e 104 is connected through an impedance matching device 106 to an antenna and to a reflector (not illustrated as it is identical with the antenna) spaced behind the antenna an odd number of quarter Wave lengths. Heating energy is supplied from a suitable source 108, in the form of a relatively low frequency power transformer, through high frequency chokes 110 to a transmission line 112 over slip rings 114 and through radio frequency choke coil 116 serially through both the antenna structure and through the reflector structure. Blocking condensers 118 are placed in line 120 in order to cause a serial flow of the low frequency energy through the antenna and reflector without impeding the passage of high frequency energy for which the blocking condensers 118 offer practically no impedance.

The antenna wires 12, 14 and 12, 14, are joined at their extremities by vertical jumpers or conductors 122, 124 and, insulators 126, 128 are inserted in the feeding jumpers 130, 132 of the antenna conductors. Each of the wires forming the tuning trap is doubled so that it consists of two wires 134, 136 and 138, 140, tied together by blocking condensers 142, 144 so that they act in parallel or as a single conductor for conducting radio frequency currents to the antenna conductors. Radio frequency short circuits 146, 148 properly tune the antenna structure, and radio frequency short circuit 150 in the form of a blocking condenser substantially one-quarter of a wave length away from feeders 151, 153

properly terminates transmission line 120.

Accordingly, it should be clear that heating energy flows through the antenna structure and also through a similar antenna structure as follows:

From transmission line 120, feeder 151, the upper portion of jumper 132 conductor 12, vertical jumper 122, conductor 12, conductor 136, short circuiting element 146, conductor 140, the lower portion of vertical jumper 130, conductor 14, vertical jumper 124, antenna conductor 14 and back again to transmission line 120 through feeder 153. Radio frequency energy, because of the various blocking condensers involved, is applied in parallel to the antenna conductors 12, 12 and 14, 14. Coupling to the radio frequency apparatus 152 is accomplished through slip rings and brushes 114 and transmission line 112 which also acts as a conductor for heating energy.

The heating circuits disclosed in the copending application of Nils E. Lindenblad, Serial Number 463,024, filed June 23, 1930, may be applied to the antenna system shown in Figures 6, 7 and 8 for heating during rotation thereof. For example, as shown in Figure 10, the antenna conductors may be terminated by half wave length and wave length conductors looped upon themselves. Heating energy may be supplied from a suitable source 154 through separate slip rings 156 to the nodal points of the half wave length loops 158 described in detail in the Linden blad application, Serial Number 463,024 rcferred to. Coupling to high frequency apparatus may be accomplished through transmission line 160, slip rings 162 and impedance matching devices 164, the slip rings 162 and the subsequent apparatus being, of course, rotatable with the antenna system.

Having thus described my invention, what I claim is:

1. In combination, a plurality of horizontal antenna conductors which are long relative to the working Wave length, supports for said conductors at the ends thereof, a rotatable mounting fixedly attached to said supports, a. shaft extending vertically through said rotatable mounting, motor mechanism for moving said shaft and mounting, remote control means for controlling the rotation of said shaft and mounting, a pointer and dial arrangement connected to said remote control means for indicating the position of said antenna conductors, slip rings mounted on said shaft and electrically connected to said antenna conductors, high frequency apparatus, and a transmission line extending between said high frequency apparatus and said slip rings.

2. In combination, a pair of horizontal linear conductors angularly disposed with respect to each other, said conductors being long relative to the working wave length, supports for said conductors at the ends thereof, a star-shaped rotatable mounting having a plurality of extending arms fixedly attached to said supports, a shaft extending vertically through said rotatable mounting for driving same, motor mechanism for moving said shaft and mounting, remote control means for controlling the rotation of said shaft and mounting, slip rings mounted on said shaft and electrically connected to said antenna conductors, high frequency apparatus, and a transmission line extending between said high frequency apparatus and said slip rings.

3. In combination, a plurality of horizonmounting, slip rings mounted on said shaft and electrically connected to said antenna conductors, high frequency apparatus and a transmission line extending between said high frequency apparatus and said slip rings.

PHILIP STAATS CARTER.

vertically 

